With a fluid pressure device such as a cylinder or the like, for example, a piston, which is arranged in the interior of a cylinder tube, undergoes advancing and retracting movements in an axial direction of the cylinder tube under the action of a fluid pressure such as air pressure or hydraulic pressure, etc.
Heretofore, with a fluid pressure device, for controlling the velocity of the piston, various velocity control structures have been adopted. For example, a velocity control mechanism equipped cylinder is known, as disclosed in Japanese Laid-Open Patent Publication No. 2004-011855 (hereinafter referred to as conventional technique 1). In the cylinder, a cylinder chamber is provided, which is closed by a cover member, and a pressure fluid is supplied with respect to the cylinder chamber from a cylinder body having a pair of ports. A piston, which is displaced along an axial direction of the cylinder chamber, is installed internally in the cylinder body, and a piston rod is connected integrally to the piston.
The cylinder includes a cylindrical body, which is arranged in the interior of the cylinder body, and is connected to the cover member substantially in parallel with the piston rod. A shaft member, which can be inserted through the interior of the cylindrical body, is connected substantially in parallel in the interior of the piston rod. The cylinder comprises a first cutout groove, which is formed along the axial direction on an outer circumferential surface of the cylindrical body, and a second cutout groove, which is formed along the axial direction along the outer circumferential surface of the shaft member. Furthermore, the cylinder comprises a first seal member that surrounds the outer circumferential surface of the cylindrical body, and a second seal member that surrounds the outer circumferential surface of the shaft member.
In addition, when the outer circumferential surface of the cylindrical body is surrounded by the first seal member, the flow rate of a pressure fluid that flows between a port and the cylinder chamber is controlled by the first cutout groove. In addition or alternatively thereto, when the outer circumferential surface of the shaft member is surrounded by the second seal member, the flow rate of the pressure fluid that flows between a port and the cylinder chamber is controlled by the second cutout groove.